1. Field of the Invention
This invention relates to gas cookers and is particularly applicable to gas cookers in the form of gas hobs or gas grill chambers. These may be independent units or may form part of a conventional multi-function cooker which may include a hob, a grill chamber, a grill/oven chamber, a single oven or a double oven or any appropriate combination thereof.
2. Description of the Prior Art
It is known to fit gas hobs with lids that open to give access to one or more burners. When closed, the lid covers the burners thereby protecting the latter and providing a "clean" line to the surface of the hob or cooker.
To allow a user to close the lid when a burner is alight is extremely dangerous. The heat from the burner will damage the lid and, if the latter is of glass, may well shatter the lid. Closure of the lid may result in extinguishment of the burner flame and the consequent escape of gas, or alternatively if the flame is not extinguished, poor combustion of the gas and damage to the lid.
Safety measures have been proposed which ensure that the supply of gas is automatically cut-off to all the hob burners when the lid is closed but such measures are not entirely satisfactory in that in some arrangements when the lid is closed with one of the gas burners alight, although the supply of gas to the burners is cut-off, when the lid is re-opened the supply of gas to the burner that was previously alight is restored, thereby allowing un-ignited gas to escape from the burner. Such an arrangement is obviously dangerous.
A similar problem can arise with gas grill chambers in which it is sometimes necessary to provide a gas control valve operated by the grill chamber door to ensure that if the grill chamber door is closed with the grill burner alight, then the gas supply to the grill burner is cut-off. However, when the grill chamber door is again opened, because the grill burner had previously been alight, un-ignited gas will be emitted from the grill burner. Again, such an arrangement is obviously dangerous.